"Dexterity is a system to create content types in Plone based on Zope 3 schema interfaces and simple content classes, with z3c.form add/edit forms. It aims to explicitly supports both through-the-web type creation with a well-defined path to filesystem code (and back)."

I'm excited about this, cant wait to see it arrive in Plone.
http://martinaspeli.net/articles/dexterity-meet-grok http://www.openplans.org/projects/plone-conference-2008-dc/dexterity